/Engine/Source/Runtime/Core/Public/Templates/Tuple.h
namespace UE { namespace Core { namespace Private { namespace Tuple { template<typename... Given, typename... Deduced> decltype([ConceptCheckingHelper](API\Runtime\Core\Templates\UE__Core__Private__Tuple__Concep-)((DeclVal< Given >()=DeclVal< Deduced && >(), 0)...)) UE::Core::Private::Tuple::AssignableConceptCheck ( Deduced && ... ) } } } }